Re: [Qemu-devel] env in TLS

[Lennert Buytenhek]

On Mon, Oct 11, 2004 at 11:41:37AM +0200, Fabrice Bellard wrote:

> Using TLS seems a good idea. I hesitated to implement it because I was 
> not sure that segment overrides were as fast as an indexed memory access 
> on all x86 processors. I think that imposing a gcc version >= 3.2 is no 
> longer an issue. We must be sure that the other platforms support the 
> __thread keyword though.

At least the ARM (xscale) doesn't, even on gcc 3.3.3.  There's also
no NPTL for ARM, probably for that reason.

address@hidden tmp]# uname -a
Linux enp2611.wantstofly.org 2.6.9-rc3 #12 Sun Oct 10 20:29:24 MEST 2004 armv4b 
armv4b armv4b GNU/Linux
address@hidden tmp]# gcc --version
gcc (GCC) 3.3.3 20040412 (Red Hat Linux 3.3.3-7)
Copyright (C) 2003 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 
address@hidden tmp]# cat x.c
#include <stdio.h>
 
int __thread xyzzy;
 
int main()
{
        return 0;
}
address@hidden tmp]# gcc -Wall -o x x.c
x.c:3: error: thread-local storage not supported for this target
address@hidden tmp]#


--L